Mechanical method and apparatus for bilateral tissue fastening

ABSTRACT

A mechanical system for bilaterally securing skin tissue preferably utilizes a tissue manipulator apparatus to approximate a portion of an interior surface of each of two pieces of living dermis tissue along a vertical interface below an exterior surface without overlapping either interior surface across the vertical interface. An applicator apparatus includes a driving head portion positioned in the vertical interface and at least partially below the exterior surface and a handle portion positioned at least partially above the exterior surface. The applicator apparatus bilaterally drives at least one portion of the fastener through each piece of the living dermis tissue behind the interior surface of that piece of tissue such that the fastener is positioned below the exterior surface and a portion of the fastener is positioned generally transverse to the vertical interface. The applicator can include guide features to direct tissue with respect to the driving head portion.

PRIORITY CLAIM AND RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 15/630,461, filed Jun. 22, 2017, which in turn is acontinuation of U.S. patent application Ser. No. 15/145,194, filed May3, 2016, which in turn is a continuation of U.S. patent application Ser.No. 14/471,519, filed Aug. 28, 2014 (now abandoned), which in turn is acontinuation of U.S. patent application Ser. No. 13/796,798, filed Mar.12, 2013 (now U.S. Pat. No. 8,821,517 issued Sep. 2, 2014), which inturn is a continuation of U.S. patent application Ser. No. 13/314,978,filed Dec. 8, 2011 (now abandoned), which in turn is a continuation ofU.S. patent application Ser. No. 11/022,319, filed Dec. 23, 2004 (nowU.S. Pat. No. 8,074,857 issued Dec. 13, 2011), which in turn is acontinuation-in-part of U.S. patent application Ser. No. 10/448,838,filed May 30, 2003 (now U.S. Pat. No. 7,686,200 issued Mar. 30, 2010),which is a divisional of U.S. patent application Ser. No. 10/179,628,filed Jun. 25, 2002 (now U.S. Pat. No. 6,726,705 issued Apr. 27, 2004),and U.S. patent application Ser. No. 11/022,319 is also acontinuation-in-part of U.S. patent application Ser. No. 10/607,497,filed Jun. 25, 2003 (now U.S. Pat. No. 7,950,559 issued May 31, 2011),and U.S. patent application Ser. No. 11/022,319 is also acontinuation-in-part of U.S. patent application Ser. No. 10/603,397,filed Jun. 25, 2003 (now U.S. Pat. No. 7,112,214 issued Sep. 26, 2006),all of which are herein incorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates generally to the field of surgicalinstruments such as surgical staplers, clip applicators and suturelessclosure devices. More particularly, the present invention relates to amechanical method and apparatus for fastening tissue, such as skintissue, with a fastener positioned below the tissue surface thatbilaterally secures opposed pieces of tissue.

BACKGROUND OF THE INVENTION

When an opening in tissue is created either through an intentionalincision or an accidental wound or laceration, biological healing of theopening commences through the proximity of the opposed living tissuesurfaces. If the opening is very large or if its location subjects thewound to continual movement, a physician will seek to forcibly hold thesides of the opening in close proximity so as to promote the healingprocess.

In the case of skin tissue, for example, healing occurs best when theopposing dermal layers of the skin tissue are held in proximity witheach other. Human skin tissue is comprised of three distinct layers oftissue. The epidermal layer, also known as the epidermis, is theoutermost layer and includes non-living tissue cells. The dermal layer,or dermis, is the middle layer directly below the epidermal layer andcomprises the living tissue of the skin that is the strongest of thethree layers. The subcutaneous, or hypodermis layer is the bottom layerof skin tissue and includes less connective tissue making this theweakest layer of skin tissue.

The most prevalent method for forcibly closing a tissue opening isthrough the use of a suture or “stitches.” As early as the secondcentury, the Greeks were using sutures to physically close skinopenings. In its simplest form, a suture is simply a length of materialthat is attached to a tissue-piercing device, such as a needle, andlooped through the opposing sides of an opening. The suture is thenpulled tight and the loop closes causing the opposing sides of thetissue to come into close physical proximity. The suture loop is heldtight by the tying of a knot or some other locking mechanism. The firstsutures were made of animal gut. Eventually other natural suturematerials including leather, horsehair, flax, cotton and silk came intouse.

As the sciences of medical and materials technology have advanced overthe course of the past century, new bioabsorbable materials have beendeveloped to further improve upon the basic suturing concept. Examplesof modern improvements to the suturing process include enhancements tothe suturing apparatus as shown, for example, in U.S. Pat. Nos.2,439,383, 2,959,172 and 3,344,790, as well as advances in sutures andsuture materials as shown, for example, in U.S. Pat. Nos. 3,123,077,3,297,033, 3,636,956, 3,792,010 4,027,676 and 4,047,533.

While traditional suturing remains a popular method of effectuatingclosure of skin openings, the use of staples and staplers as a skinclosure technique has become increasingly popular, especially insurgical settings where the opening is created through a purposefulincision. In these settings, the incision tends to make a clean,straight cut with the opposing sides of the incision having consistentand non-jagged surfaces. Typically, stapling of a skin opening, forexample, is accomplished by manually approximating the opposing sides ofthe skin opening and then positioning the stapler so that a staple willspan the opening. The stapler is then manipulated such that the stapleis driven into the skin with one leg being driven into each side of theskin and the cross-member of the staple extending across the openingexternal to the skin surface. Generally, the legs of the staple aredriven into an anvil causing the staple to deform so as to retain theskin tissue in a compressed manner within the staple. This process canbe repeated along the length of the opening such that the entireincision is held closed during the healing process.

Much work has been devoted to improving upon the basic stapling process.Developments have gone in a variety of directions and include workdevoted to the stapling apparatus as shown, for example, in U.S. Pat.Nos. 3,082,426, 3,643,851, 4,410,125, 4,493,322, 4,592,498, 4,618,086,4,776,506, 4,915,100, 5,044,540, 5,129,570, 5,285,944, 5,392,979,5,489,058, 5,551,622, 5,662,258, 5,794,834, 5,816,471, 6,131,789 and6,250,532. In addition to the stapling apparatus, developments have alsobeen made in the staple design as shown, for example, in U.S. Pat. Nos.2,351,608, 2,526,902, 2,881,762, 3,757,629, 4,014,492, 4,261,244,4,317,451, 4,407,286, 4,428,376, 4,485,816, 4,505,273, 4,526,174,4,570,623, 4,719,917, 4,741,337, 5,007,921, 5,158,567, 5,258,009,5,297,714, 5,324,307, 5,413,584, 5,505,363 and 5,571,285.

While modern suturing and stapling techniques continue to provide aneffective manner of effectuating skin closure, there remains a series ofinherent disadvantages in using either of these techniques. The standardtechnique for both suturing and stapling includes puncturing both theepidermis and dermis. This can result in a wound closure having anunaesthetically pleasing appearance on the surface of the skin. Thepresence of the fastener exposed through the skin surface provides anopportunity for infection and for accidentally catching the fastener andtearing the wound open. In the case of non-absorbable fasteners, furtheraction by a medical professional is necessary in order to remove thefastener once biological healing is complete.

In order to overcome these limitations, practitioners have developed anumber of specialized suturing techniques where the suture is passedonly through the dermis effectively positioning the suture below theskin surface, or in a subcuticular fashion. A surgeon has the choice ofplacing individual or interrupted sutures along the length of anopening. Another suturing option is for the surgeon to use a singlestrand of suture material to place a plurality of continuing sutureloops or running sutures along the length of an opening. While thepresence of the suture below the surface can improve the aestheticnature of the closure, it requires greater skill and technique toaccomplish effectively and takes longer than conventional externalsuturing.

While there has been active development of dermal layer suturingtechniques, little has been done in the area of staples and staplers foruse in connection with the dermal layer. In a series of patents issuedto Green et al., including U.S. Pat. Nos. 5,292,326, 5,389,102,5,489,287 and 5,573,541, a subcuticular stapling method and apparatusare disclosed that were ultimately commercialized as the U.S. SurgicalSQS Subcuticular Stapling Apparatus. The Green et al. patents describe astapling technique employing a handheld apparatus with jaws toproximate, interdigitate and overlap opposing sides of dermal layertissue along the length of a skin opening. The apparatus then drives asingle spike through the interdigitated and overlapped dermal layers ofthe opposing skin surfaces in order to secure both sides of the dermaltissue on the single spike. Although this technique reduced the timerequired to effectuate a subcuticular skin closure, the SQS device wasnot commercially successful in part because the resulting closureproduced an undesirable wave-like scar that sometimes did not healeffectively.

While many improvements have been made to mechanical tissue closuretechniques, it would be desirable to provide a mechanical tissue closuresystem that is capable of effectively delivering fasteners below theskin surface so as to produce an efficient and efficacious tissueclosure.

SUMMARY OF THE INVENTION

The present invention is a mechanical system for bilaterally securingskin tissue. Preferably, a tissue manipulator is used to approximate aportion of an interior surface of each of two pieces of living dermistissue along a vertical interface below an exterior surface withoutoverlapping either interior surface across the vertical interface. Anapplicator apparatus includes a driving head portion positioned in thevertical interface and at least partially below the exterior surface,and a handle portion positioned at least partially above the exteriorsurface. The applicator apparatus bilaterally drives at least oneportion of the fastener through each piece of the living dermis tissuebehind the interior surface of that piece of tissue such that thefastener is positioned below the exterior surface and a portion of thefastener is positioned generally transverse to the vertical interface.

Unlike existing mechanical tissue fastening systems, the presentinvention recognizes the need for and advantages of a fastener systemthat captures and retains dermal tissue in a compressed state within apreferably bioabsorbable fastener that is not inserted through theepidermal skin layer. The mechanical fastening system of the presentinvention is able to consistently and repeatedly interface a fastenerwith a target tissue zone in the dermal layer such that the fastenerinserted into the target tissue zone produces an effective andaesthetically pleasing closure of a tissue opening.

In another aspect of the invention, an embodiment of a subcuticular skinstapler can include a head portion adapted to engage skin tissue forfastening having a upper and lower tissue guide members for improvinginsertion and retention of skin tissue within a capture area throughwhich a bioaborbable fastener/staple is introduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a typical opening in skin tissue such as may be closed bythe present invention.

FIG. 2 shows a cross-sectional view of the skin tissue and opening ofFIG. 1.

FIG. 3 shows a cross-sectional view of everted skin tissue.

FIG. 4 shows a perspective cross-sectional view of an opening in skintissue at rest, indicating optimal bilateral target tissue zones.

FIG. 5 shows an enlarged view of a target tissue zone.

FIG. 6 shows the view of FIG. 4 with the skin tissue everted.

FIG. 7 is a perspective view of an embodiment of the applicatorapparatus of the present invention.

FIG. 8 is a perspective view of the lower handle and driving headportions of the applicator apparatus of FIG. 7.

FIG. 9 is a top plan view of the lower handle and driving head portionsof the applicator apparatus of FIG. 7.

FIG. 10 is a partial cross-sectional view of the driving head portionshown in FIG. 9.

FIG. 11 is a side elevation view of the lower handle and driving headportions of the applicator apparatus of FIG. 7.

FIG. 12 is a perspective view of the lower handle and driving headportions as depicted in FIG. 8 with a fastener positioned therein.

FIG. 13 is another perspective view of the lower handle and driving headportions as depicted in FIG. 8 with a fastener positioned therein.

FIG. 14 is a phantom view of the applicator apparatus of an embodimentof the present invention having an automated fastener delivery andstorage mechanism.

FIG. 15 is an enlarged phantom view of the apparatus of FIG. 14.

FIG. 16 is a partial view of the apparatus of FIG. 14.

FIG. 17 is a perspective view of an embodiment of a manipulatorapparatus according to the present invention.

FIG. 18 is an enlarged view of the jaw portions of the manipulatorapparatus of FIG. 17.

FIG. 19 is a perspective view of an embodiment of a fastener accordingto the present invention.

FIG. 20 is a top plan view of the fastener depicted in FIG. 19.

FIG. 21 is a perspective view showing the orientation of applicator andmanipulator apparatus during a step of an embodiment of the method ofthe present invention.

FIG. 22 is a perspective view of the apparatus during another step of anembodiment of the method of the present invention.

FIG. 23 is a perspective view of the apparatus during yet another stepof an embodiment of the method of the present invention.

FIG. 24 is a perspective view of the apparatus during still another stepof an embodiment of the method of the present invention.

FIG. 25 is a top plan view of an alternative embodiment of a fasteneraccording to the present invention.

FIG. 26 is a side elevation view of the fastener of FIG. 25.

FIG. 27 is a view of the fastener of FIG. 25 in a deployed condition.

FIG. 28 is a view of an applicator assembly according to an alternativeembodiment of the invention.

FIG. 29 is another view of an applicator assembly according to analternative embodiment of the invention.

FIG. 30 is a pictorial representation of a skin opening closed withconventional subcutaneous sutures.

FIG. 31 is a pictorial representation of a skin opening closed byconventional surgical stapling.

FIG. 32 is a pictorial representation of an opening closed with theprior art interdigitated subcuticular stapler.

FIG. 33 is a pictorial representation of an opening closed using thebilateral fastening technique of the present invention.

FIG. 34 is a longitudinal cross-sectional view of an alternativeembodiment of the present invention showing operation of correspondingguiding features on the tissue manipulator and the applicator.

FIG. 35 is a longitudinal cross-sectional view of an alternativeembodiment of the present invention showing ball tip ends on the tissuemanipulator and corresponding semi-spherical areas on the applicator.

FIG. 36 is a top cross-sectional view of the alternative embodimentshown in FIG. 35.

FIG. 37 is an isometric view of an alternate embodiment of theapplicator assembly in which the fasteners are inserted obliquely intothe tissue.

FIG. 38 is an isometric view of an alternate embodiment of the presentinvention in which the tissue manipulator and the applicator assemblyare incorporated in a single handheld instrument. FIG. 39 is a plan viewof an embodiment of a fastener showing the inner cross-sectional area.

FIG. 40 is an exploded perspective view of an alternative embodiment ofthe present invention in which a tissue manipulator assembly and anapplicator assembly are incorporated into a single handheld surgicalinstrument.

FIG. 41 is a side view of the handheld surgical instrument shown in FIG.40.

FIG. 42 is a side view of the handheld surgical instrument shown in FIG.40.

FIG. 43 is a perspective view of the handheld surgical instrument shownin FIG. 40.

FIG. 44 is a perspective view of the handheld surgical instrument shownin FIG. 40.

FIG. 45 is a side view of a tissue form.

FIG. 46 is a perspective view of the tissue form shown in FIG. 45.

FIG. 47 is a side view of an insertion block.

FIG. 48 is a perspective view of the insertion block shown in FIG. 47.

FIG. 49 is a front view of the insertion block shown in FIG. 47.

FIG. 50 is a top view of an alternative embodiment of a surgicalfastener.

FIG. 51 is a perspective view of an alternative embodiment of a surgicalfastener.

FIG. 52 is a top view of the handheld surgical fastener of FIG. 40loaded with a surgical fastener.

FIG. 53 is a top view of a pair of piercing members and a backspanloaded with a surgical fastener.

FIG. 54 is a perspective view of a piercing member.

FIG. 55 is a perspective view of an arm tip.

FIG. 56 is a side view of the handheld surgical instrument of FIG. 40.

FIG. 57 is a perspective view showing a tissue positioning step of thethrough-and-through bilateral fastening technique of the presentinvention.

FIG. 58 is a perspective view showing a tissue positioning step of thethrough-and-through bilateral fastening technique of the presentinvention.

FIG. 59 is a perspective view showing a tissue positioning step of thethrough-and-through bilateral fastening technique of the presentinvention.

FIG. 60 is a perspective view showing a tissue capture and forming stepof the through-and-through bilateral fastening technique of the presentinvention.

FIG. 61 is a perspective view showing a tissue capture and forming stepof the through-and-through bilateral fastening technique of the presentinvention.

FIG. 62 is a side view of the handheld surgical instrument of FIG. 40.

FIG. 63 is a perspective view of a wound closure following insertion ofsurgical fasteners using the through-and-through bilateral fasteningtechnique of the present invention.

FIG. 64 is a side view of an alternative embodiment of the presentinvention in which a tissue manipulator assembly and an applicatorassembly are incorporated into a single handheld surgical instrumenthaving a multi-shot fastener insertion design.

FIG. 65 is a sectional, perspective view of the handheld, multi-shotsurgical instrument of FIG. 64.

FIG. 66 is a sectional, side view of the handheld multi-shot surgicalinstrument of FIG. 64.

FIG. 67 is a front, partial section view of the handheld multi-shotsurgical instrument of FIG. 64.

FIG. 68 is a perspective, partial section view of the handheldmulti-shot surgical instrument of FIG. 64.

FIG. 69 is a perspective, partial end view of an embodiment of asubcuticular skin stapler.

FIG. 70 is a perspective, partial end view of an embodiment of asubcuticular skin stapler.

FIG. 71 is a perspective, partial end view of an embodiment of asubcuticular skin stapler.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIGS. 1-3 there is shown a depiction of a typical opening 50 in thesurface of skin 52, such as may be made, for example, by a surgicalincision or a wound. As illustrated in FIG. 1, for purposes ofdescribing the present invention, opening 50 may be described as havinga length or longitudinal orientation parallel to the y-y axis, a widthorientation parallel to the x-x axis, and a depth orientation parallelto the z-z axis. The x-y-z axis for purposes of the present invention isdefined with respect to an external tissue surface, which in the case ofskin 52 is the outer surface. References to a vertical and horizontalplanar orientation in connection with the present invention are madewith respect to the external tissue surface at the site of the openingin question. The vertical inner surfaces 60 formed by each side of theopening 50 can be visualized as meeting along a generally verticalinterface 51. It will be understood that in the case of an opening thatextends over a curved tissue surface, the corresponding horizontal andvertical surfaces associated with the opening will be defined withrespect to such curved tissue surface. It also will be understood thatthe vertical interface 51 may be vertical in only one orientation withrespect to the tissue surface, such as in the case when an angledincision has formed the opening 50.

As is best illustrated in the sectional views of FIGS. 2 and 3, humanskin 52 generally has three discrete layers. These layers comprise anepidermal layer 54 of mostly non-living tissue having an exteriorsurface 55, a dermal layer 56 of mostly living tissue, and asubcutaneous tissue layer 58. Although the preferred embodiment of thepresent invention will be described with respect to human skin tissue52, it will be understood that the present invention is applicable toclosure of openings in other types of tissue having generally definedsurfaces, such as fascia, membranes organs, vessels, vasculature,vascular pedicles, skin grafts, bladder and other biocompatiblematerials with generally defined surfaces such as artificial skin,artificial membranes and synthetic mesh.

It has long been known that the most rapid healing of a skin openingwith a minimum of scarring occurs when the inner surfaces 60 of theliving dermal layer 56 at each side of the vertical interface 51 of skinopening 50 are brought together and held in close contact in what isreferred to as an everted position as is shown in exaggerated fashion inFIG. 3. To the extent that the primarily non-living material ofepidermal layer 54 can be excluded from the healing opening, therapidity and level of scar tissue formed during the healing process willbe improved.

The ability of the present invention to provide a more effective andefficacious tissue closure can be seen with reference to FIGS. 30-33,which show skin openings closed by various prior art methods as comparedwith an opening closed using the bilateral fastening techniques of thepresent invention. In FIG. 30, there is shown a skin opening closed withsubcutaneous sutures. The generally everted condition of the closedopening can produce unattractive scarring and less than optimal healingif the eversion is excessive or inadequate. As can be seen from FIG. 30,obtaining consistency from suture to suture is difficult and the qualityof the closure is highly dependent upon the skill of the surgeon. FIG.31 shows a skin opening closed by conventional surgical stapling. Inaddition to the generally unattractive appearance of the closed opening,staple openings and the excessive everted condition of the opening maylead to undesirable scarring. In addition, if non-resorbable staples areused, the staples must be removed before complete healing can occur.FIG. 32 shows a depiction of an opening closed with the interdigitatedsubcuticular stapler known as the SQS device that is described, forexample, in U.S. Pat. Nos. 5,292,326, 5,389,102, 5,489,287 and5,573,541. The characteristic undulating appearance caused by theoverlapping interdigitation of the skin may lead to an unusual appearingscar in the healed opening. The overlapping and interdigitation of theskin can also cause epidermis tissue to be interposed between dermallayers, thereby leading to incomplete healing or excessive scarring.

By comparison, an opening that has been partially closed by the methodand using the apparatus of the present invention is shown in FIG. 33. Asshown, the closed portion of the opening is tightly closed, yet liesflat without undue eversion of the opening leading to better healingperformance with minimal scarring. There is consistency in the closurefrom fastener to fastener. Because the fasteners are positioned belowthe skin surface (i.e., subcuticular), the fasteners are not exposed andthere is no puncturing or button holing of the epidermis that can leadto the increased possibility of infection or interference with thenormal healing process. In addition, if fasteners made of abioresorbable, bioabsorbable or even a bioerodible material are used,there is no need to later remove the fasteners.

The advantages of the present invention are accomplished by an apparatusand method that bilaterally engages target tissue zones 70 on each sideof a skin opening 50 with a fastener that is preferably made of abioresorbable material. As used in connection with the presentinvention, the term bilateral refers to at least two axis of insertionfor a fastener that are on separate sides of the vertical interface 51of an opening 50. The bilateral engagement may be made eithersimultaneously or sequentially, and the fastener used may have a varietyof configurations and be oriented in a variety of ways as will befurther described herein. The location, geometry and orientation of thefastener and the dermal layers in relation to the mechanical apparatusof the present invention are all important considerations to obtainingthe most optimal contact and compression of the dermal layer forefficacious closing of the opening. While the skin opening 50 will bedescribed in connection with an opening in a single piece of tissue, itwill be understood that the opening 50 could also be between twoseparate and otherwise unconnected pieces of tissue, or even between apiece of tissue and a piece of biocompatible material to be secured tothat piece of tissue.

As is shown in FIGS. 4 and 5, there exists an optimal target tissue zone70 on each side of vertical interface 51 that may be bilaterally engagedby a fastener in order to achieve optimal dermal contact for healing.This target tissue zone 70 lies within the dermal layer 56, and can bevisualized as a rectangular cross-sectional area when the tissue is in arelaxed condition as shown best in FIG. 4. In addition, within targettissue zone 70, there exists a most preferred area 72 for tissueengagement. In the depth orientation, target tissue zone 70 lays betweena distance L3 of about 0.1 mm below the surface 55 of epidermal layer54, and a distance L4 up to 2.0 mm below the surface 55. The mostpreferred area 72 lies between a distance L5 of about 0.2 mm and adistance L6 of about 0.8 mm below the surface. In the width orientation,target tissue zone 70 lies between a distance L7 of about 1.0 mm and adistance L8 of about 20.0 mm from vertical interface 51. Most preferredarea 72 lies between a distance L9 of about 2.0 mm and a distance L10 ofabout 8.0 mm from vertical interface 51. Because the target tissue zone70 is not visible to an operator, the manipulator assembly 400 andapplicator assembly 100 are preferably designed to consistently andrepeatedly enable the operator to position the target tissue zone 70 fordeployment of a fastener 400.

As illustrated in FIG. 6, due to the inherent flexibility and resilienceof skin tissue, it is most desirable that a fastener 400 be deployedinto the target tissue zone 70 while the skin opening is everted. Bycompressing the everted dermal layers 56 on either side of the opening50 into the fastener 400, the dermal layers 56 are retained in closecontact with each other by the fastener 400 after the everting pressureis removed and the skin relaxes into a flat condition as shown in FIG.4.

An embodiment of the apparatus of the present invention is shown inFIGS. 7-20. Generally, the apparatus includes an applicator assembly100, a tissue manipulator assembly 300, and a fastener 400.

An embodiment of applicator assembly 100 is shown in FIGS. 7-16. Theassembly generally comprises upper handle portion 110 and lower handleportion 120, to which is attached driving head 140. Trigger 200, whichpivots about pivot 202 is provided to allow user actuation of themechanism. Although a manual pivoting trigger arrangement 200 is shown,it will be understood that a variety of other user-actuated manualtriggers, buttons or actuator mechanisms may be utilized with theapplicator assembly 100, such as a push button, slide mechanism, cammechanism, spring actuated apparatus, cable actuated pull mechanism,rotating mechanism or tab actuated trigger. Alternatively, an automaticactuator in the form of an electronic, pneumatic, motion controlled,remote controlled or computer-activated trigger may be used to operatethe applicator 100.

In FIGS. 8-13, there are shown detailed views of an embodiment of adriving head 140 and lower handle portion 120. Driving head 140 ispreferably U-shaped and has an anvil portion 142 separated from backingportion 144 by a cross-member 146, thereby forming a gap 148.Cross-member 146 preferably has concave areas 150, which are shaped tocorrespond to tissue manipulator surfaces 318 of tissue manipulatorassembly 300, allowing the dermal layer 56 of skin to be compressed intocontact within gap 148, and with target tissue zones 70 present forcapture on either side of vertical interface 51 as will be furtherexplained hereinbelow. Although driving head 140 is shown in a fixedorientation relative to lower handle portion 120 and upper handleportion 110, it will be understood that driving head 140 may bearticulated, either in the plane of the vertical interface 51 orperpendicular to the plane of the vertical interface 51, to allow forincreased maneuverability and orientation of driving head 140.Alternatively, lower handle portion 120 may be articulated relative toupper handle portion 110, or both lower handle portion 120 and drivinghead 140 may be articulated.

Preferably, anvil portion 144 of driving head 140 has apertures 152formed therethrough. Apertures 152 are appropriately sized so as toslidingly receive penetrators or pilot needles 154, 156 and may be boredirectly into the material of anvil portion 144 or may be lined with ametal guide tube or the like inserted into a bore in anvil portion 144.Pilot needles 154, 156 have a generally arcuate shaped cross-sectionthroughout distal portions 155, 157, and a solid cylindricalcross-section in proximal portions 159, 161. Each distal portion 155,157 has an inner concave surface 158, 160 for accommodating andretaining a fastener 400, and each proximal portion 159, 161 engages theback surface of the fastener 400, allowing the fastener to be advanceddistally with the needles. The distal ends 162, 164 of pilot needles154, 156 have a sharp point for penetrating skin. Pilot needles 154, 156are vertically disposed at a distance dl below top surface 166 of anvilportion 142. It is preferably that top surface 166 be usable as areference datum for visually gauging whether pilot needles 154, 156 arelocated within target tissue zone 70. Accordingly, it is preferable thatdistance dl be between 0.1 mm and 2.0 mm, and most preferably between0.2 mm and 0.8 mm, so that when top surface 166 is aligned with theouter skin surface, pilot needles 154, 156 are located within targettissue zone 70 and most preferably within most preferred area 72.

Delivery mechanism 128 serves to eject a fastener from driving head 140.Preferably, slide block 122 is slidably mounted on guides 124, 126,within lower handle portion 120. Slide block 122 is engaged with trigger200 so that actuation of the trigger causes sliding movement of slideblock 122. Pilot needles 154, 156 are fixedly attached to slide block122, and extend outwardly through backing portion 144 of driving head140 through slot 168. Thus, back and forth sliding motion of slide block122 causes pilot needles 154, 156 to be extended and retracted from slot168, gap 148 and apertures 152. It will be understood that any number ofmechanical driving arrangements can be used to impart the necessaryforce to pilot needles 154, 156, or alternatively to the fastener 400directly. Examples include sliding mechanisms, cam mechanisms,spring-operated mechanisms, screw drives, pneumatic drives, automatedmotion control drives, or the like.

Pilot needles 154, 156 are preferably spaced apart by an interneedledistance of between about 2.0 mm and 20 mm and most preferably betweenabout 4.0 mm and 16.0 mm, so that when the driving head in placed withina skin opening to be fastened, and with the skin opening aligned withthe approximate midpoint between the pilot needles, the pilot needleswill be located within the width orientation of the target tissue zone70.

Although single fasteners may be inserted manually one-by-one betweenpilot needles 154, 156, an alternative embodiment of applicator assembly100, shown in phantom in FIGS. 14-16 has an automated fastener deliveryand storage mechanism 220. In this mechanism, fasteners are preferablystacked vertically in echelon fashion surrounding a guide member 224,and are biased downwardly with a resilient member such as a spring (notshown). Housing 222 is provided to protect the mechanism. Thebottom-most fastener in the echelon is engaged with pilot needles 154,156. As each fastener 400 is emplaced in the skin through operation ofthe applicator assembly 100 as described herein, and slide block 122 isreturned to the proximal limit of travel, the downward bias of theechelon causes the immediately vertical adjacent fastener to movedownward and become engaged within pilot needles 154, 156. The nextfastener may then be emplaced in the skin, and the process repeated.Again, it will be appreciated that numerous arrangements andconfigurations for providing and deploying multiple fasteners within thecontext of the present invention could be used, such as inline stackingin either a horizontal or vertical orientation, side-by-side stacking,rotational presentation via a circular chamber or magazine or belt ortape-attached presentation of the fasteners 400.

In FIGS. 17 and 18, there is shown an embodiment of the tissuemanipulator assembly 300 of the present invention. The proximal ends 307of arms 302, 304 are joined together at fulcrum 306, forming thetweezer-like structure of the overall assembly. Gripping areas 312 areprovided on each arm to allow gripping of the assembly with the fingers.Any suitable fastening method may be used at fulcrum 306, includingrivets 316 as shown, or the arms 302, 304 may be welded, cast, or moldedtogether or may otherwise be integrally formed together. The materialand overall dimensions for arms 302, 304 are selected so as to allow thearms to be resiliently compressed inwardly with the fingers, and with amemory characteristic for returning to the original position upon theremoval of pressure. In addition, the material used for the arms andother portions of the assembly are preferably thermally and chemicallystable so as to allow sterilization with either heat or chemical means.The preferred material for arms 302, 304 is stainless steel.

At the distal ends 309 of each arm 302, 304 are formed tissuemanipulator surfaces 318. Manipulator surfaces 318 are preferablysemi-cylindrically shaped as shown, with the diametrical dimension ofeach semi-cylinder selected so as to conform to the diameter and shapeof the concave areas 150 of applicator assembly 100. Skin gripping jawmembers 314 are preferably attached to the exterior surfaces 326 of eacharm member 302, 304. Each jaw member 314 has a backing portion 324 forattaching to the arms, and a pair of inwardly directed projections 320disposed on both sides of manipulator surfaces 318. Directly opposedserrations 322 are preferably provided on the inward-most edge of eachprojection 320 for better skin purchase. Backing member 324 may beattached to each arm 302, 304 using any suitable attachment method,including mechanical fasteners such as the rivets 316 as shown. Forreasons that will be further explained, it is preferable that each jawmember 314 is of sufficient resilience and is attached so that inwardlydirected projections 320 may deflect separately from skin manipulatorsurfaces 318 under moderate finger pressure applied to arms 302, 304.This may be achieved through concerted selection of the material usedfor jaw member 314, the thickness dimension of backing member 324, andthe free length L1 of each backing member 324 between the inwardlydirected projections 320 and the fastener 316 closest to the distal end309 of the arm. The objective of the design of the backing member 324 isto have the jaw members 314 engage tissue with a first force and havethe manipulator surfaces 318 engage tissue between the jaw members 314with a second force that is greater than the first force. In addition,the use of a pair of directed projections 320 on each side of thevertical interface 51 serves to stabilize the tissue laterally betweenthe pair of projections 320.

Mechanical stops 330 are provided to prevent pressure beyond thatnecessary to ensure optimal approximation of tissue into gap 148 andconcave portions 150 of applicator assembly 100 from being transmittedthrough manipulator surfaces 318. Preferably, mechanical stops 330 areset so that manipulator surfaces 318 close to a distance that is spacedapart from the inter-needle distance of pilot needles 154, 156 by arange of 0.2-0.8 millimeters, such that the total distance betweenmechanical stops 330 is 0.4-1.6 millimeters greater than the interneedledistance between pilot needles 154, 156. In a preferred embodiment inwhich the interneedle distance is set at 3.25 millimeter, the mechanicalstops 330 would allow the surfaces 318 to close to within a range of3.65-4.85 millimeters when approximating tissue into gap 148. Althoughjaw members 314 may be formed from any suitable material, the preferablematerial is stainless steel.

In FIGS. 19 and 20, there is shown an embodiment of a fastener 400 ofthe present invention. Fastener 400 has body portion 402, whichcomprises a cross-member 408 connecting a pair of fork members or legs406. The outer margins 410 of each leg 406 are dimensioned and shapedaccommodatingly to the inner concave surfaces 158, 160, of pilot needles154, 156, allowing fastener 400 to fit and slide between the distalportions 155, 157 of the needles, as is shown best in FIGS. 12 and 13.Shoulders 414 preferably are provided to engage the solid cylindricalcross-section of the proximal portions 159, 161 of pilot needles 154,156, thus allowing fastener 400 to be advanced distally with motion ofthe needles. The distal end 412 of each leg 406 is incurvately shaped toallow easier passage through an opening in skin, referred to as a skive,that is created by pilot needles 154, 156. Inwardly directed barbs 404preferably are provided on each leg 406 to resist withdrawal of thefastener once emplaced.

Although an overall U-shape for the fastener 400, as shown in FIGS. 19and 20 is preferred, other shapes having a capability for bilateraltissue engagement are also possible and within the scope of theinvention. Such other shapes include for example, but are not limitedto, a square shape similar to an ordinary staple, a semi-circular orC-shape or a V-shape or W-shape, in which the cross-member 408 has bendsor other features. While the shape of fastener 400 is generallydetermined in a planar configuration, it will be recognized that othernon-planar shapes and configuration can be used, such as a fastenerhaving multiple projections for each leg 406, with each projectionoriented in a different plane, or a fastener having cross-member 408arranged in a V-shape projecting out of the normal plane of the fastener400. Two leg members 406 are preferred, but it will be understood thatadditional leg members 406 could be added in the same or a differentplane of the fastener 400 such that the leg members of each side of thefastener form a dident or trident configuration, for example.

As shown in FIG. 39, an inner cross-sectional area 409 is defined by thefastener 400 for capturing the compressed dermal tissue. In a preferredembodiment, inner cross-sectional area 409 ranges from 1.5 sq. mm to 50sq. mm and most preferably about 5 sq. mm to 10 sq. mm. This area isgenerally defined by an inner diameter length of between 1.5 mm and 9 mmand most preferably about 3.8 mm and an inner diameter width of between1 mm and 5 mm and most preferably about 2 mm. It will be apparent thatnumerous shapes and configurations can be used for the shape andarrangement of cross-sectional area 409. Preferably, innercross-sectional area 409 is generally arrowhead shaped as a result ofthe positioning of the barbs 412. As will be described, the barbs 412 orsimilar anti-reversing projections resist against the withdrawal offastener 400. While the barbs 412 are preferably oriented into the innercross-sectional area 409, it will be appreciated that barbs 412 may beomitted or may be oriented outwardly.

Although it is possible for fastener 400 to be deformed during deliveryand application, preferably the majority of dermal tissue retainedwithin cross-sectional area 409 is captured in a compressed state by afastener 400 that is sufficiently rigid so as to retain the dimensionalintegrity of cross-sectional area 409 within +/−30% of its designed areafor a period of preferably at least 10 days. Most preferably, structuralintegrity of fastener 400 is maintained for at least 21 days. In thisway, the dermal tissue captured in fastener 400 is retained in acompressed state for a period sufficient to allow the biological healingprocess to occur without the dermal tissue being under tension duringthe healing process. Preferably, the dimensions of the fastener 400 andthe operation of the applicator assembly 100 coordinate to create acompression ratio of dermal tissue within the inner cross-sectional area409 that is greater than one. The compression ratio is defined either asa ratio of area or a ratio of width. In the case of width, thecompression ratio is the ratio of the dimension defined by the positionof the skive relative to the vertical interface 51 when the dermaltissue is at rest divided by the position of the skive relative to thevertical interface as held by the fastener 400. In the case of area, thecompression ratio is the ratio of the area of dermal tissue that will beretained by the fastener 400 when that dermal tissue is at rest dividedby the actual cross-sectional area 409.

Alternatively, it is possible to take advantage of the bilateral tissuefastening in the tissue target zone as taught by the present inventionwith a deformable fastener where the deforming of a bioresorbable orbioabsorbable fastener serves to provide at least some of thecompression of the dermal tissue such that the need for a mechanicaltissue manipulator is reduced or potentially eliminated. In thisembodiment, a bioresorbable or bioabsorbable fastener would be deformedby the applicator apparatus in order to appropriately compress thedermal tissue. Deformation of a bioresorbable or bioabsorbable fastenercould be accomplished in a number of ways, including prestressing thefastener into an open configuration such that it returns to a closedconfiguration, with or without mechanical assistance from theapplicator, application of ultrasound, heat or light energy to alter theshape of, or reduce or relax stresses in, the fastener in situ,designing a polymer material with appropriate shapes and compositionsthat the material is deformable upon deployment without fracturing, orany combination of these techniques.

Fastener 400 is preferably formed from any suitable biodegradablematerial. The currently most preferred biodegradable material is alactide/glycolide copolymer where the ratio is never less than at least10% of one element and preferably in a range of 60%-70% lactide.Examples of other suitable materials include poly(dl-lactide),poly(l-lactide), polyglycolide, poly(dioxanone),poly(glycolide-co-trimethylene carbonate), poly(l-lactide-co-glycolide),poly(dl-lactide-co-glycolide), poly(l-lactide-co-dl-lactide) andpoly(glycolide-co-trimethylene carbonate-co-dioxanone). In addition,other suitable materials could include compositions with naturallyoccurring biopolymers such as collagen and elastin, or stainless steel,metal, nylon or any other biocompatible materials in the case of anon-absorbable fastener, or even various combinations of such materialsdepending upon the desired application and performance of the fastener.

With reference to FIGS. 21-24, the operation of the apparatus of thepresent invention may now be explained and understood. A fastener 400 isfirst loaded between pilot needles 154, 156, as shown in FIG. 12. Slideblock 122 is then proximally retracted to the fullest extent so thatpilot needles 154, 156 and the fastener 400 are entirely within slot168. Driving head 140 is then introduced into skin opening 50 and topsurface 282 is aligned with the outer surface of the skin as shown inFIG. 21. Tissue manipulator assembly 300 is placed with jaw members 314on either side of driving head 140. Arms 302, 304 of manipulatorassembly 300 are pressed inward so that jaws 314 engage the skin surfaceand begin to force the skin 52 into gap 148 in applicator assembly 100as shown in FIG. 22. Serrations 322 provide purchase on the skin surfaceand prevent lateral slipping of the skin relative to the jaws. Asfurther inward pressure is applied to arms 302, 304, inwardly directedprojections 320 engage side surfaces 170 of anvil portion 142 and sidesurfaces 172 of backing portion 144, each with a single thickness ofskin trapped between as shown in FIG. 23. Still further inward pressureon arms 302, 304, as shown in FIG. 24, causes tissue manipulatorsurfaces to deflect inward slightly from jaws 314, until each engagesconcave area 150 of cross-member 146 with a layer of skin trapped inbetween. In this position, inner surfaces 60 of dermal layer 56 are indirect contact with each other within gap 148 and substantially parallelwith vertical interface 51, but are not overlapped or interdigitated.

In this embodiment, pilot needles 154, 156 are aligned generallyhorizontally and substantially parallel with the outer surface of theskin and are within target tissue zone 70. Cross-member 408 of fastener400 is positioned generally transverse to vertical interface 51 and aworking plane of fastener 400 defined by cross-member 408 and legs 406is generally horizontal in orientation. Trigger 280 is then actuated,causing slide block 122 to move proximally within lower handle portion120, and advancing pilot needles 154, 156 into the skin, creating askive through the target tissue zone 70 of the skin on each side ofvertical interface 51. Fastener 400 moves with pilot needles 154, 156,and each leg 406 of the fastener 400 is simultaneously driven into andthrough the skive. Once fastener 400 is advanced distally a sufficientdistance so that barb tips 416 of fastener 400 enter apertures 152 andaccordingly emerge from the skive, trigger 280 may be reversed so thatslide block 122 moves proximally, retracting pilot needles 154, 156.Barbs 412 engage the skin, thereby preventing fastener 400 from beingwithdrawn with the pilot needles. Once slide block 122 has been fullyretracted proximally, thereby causing pilot needles 154, 156 to be fullyretracted from gap 148, the pressure on manipulator assembly 300 may bereleased and applicator assembly 100 can be moved proximally in theopening 50 to deliver another fastener 400 or can be removed fromopening 50.

In addition to the embodiment of the apparatus described above whereinthe legs of a fastener are simultaneously driven through the targettissue zone on each side of the skin opening and with the fastener legsoriented parallel to the epidermal skin surface, those of skill in theart will appreciate that other embodiments of a mechanical fasteningsystem for openings in skin tissue are within the scope of the presentinvention. For instance, the working plane of fastener 400 defined bycross-member 408 and legs 406 may be oriented generally orthogonal, oroblique in at least one orientation, to the horizontal plane generallydefined by exterior surface 55 of epidermal layer 54. In such anembodiment, fastener 400 may be inserted in a generally verticalorientation with legs 406 pointing generally in an upward direction orin a downward direction.

Another embodiment of the apparatus of the present invention wherein afastener is driven sequentially through the bilateral target tissuezones is shown in FIGS. 25-29. In one embodiment, fastener 500 hasflexible body portion 502 with a barb 506 at distal end 505 and anattachment flap 504 at proximal end 503. Flexible body portion 502 isdimensioned so as to be received within either concave inner surface158, 160 of pilot needles 154, 156. Attachment flap 504 has slot 508formed therethrough, which is adapted to receive barb 506. In applicatorassembly 100, anvil portion 142 has concave deflector 153 formed betweenapertures 152 and extending into a portion of each aperture 152 so thatonly an area of each aperture is open sufficient to allow the arcuatecross-section of pilot needles 154, 156 to pass. In operation, and withreference to FIGS. 1-29, fastener 500 is axially aligned with pilotneedle 154, and is inserted within the corresponding concave innersurface of the needle with barb 506 oriented toward the point of theneedle. Applicator assembly 100 is then introduced into the interfaceportion 51 of the skin opening 50 as described above. Tissue manipulatorassembly 300 is then applied as before to bring the dermal layer 56 intocontact within gap 148, and thereby properly positioning target tissuezone 70. As slide block 122 and the attached pilot needles 154, 156 aremoved distally through actuation of trigger 280, fastener 500 isadvanced through the skin tissue on one side of skin opening 50 alongwith pilot needle 154 in which it is disposed. Once the tip of barb 506reaches aperture 152, however, it is engaged by, and begins to slidelaterally along, concave deflector 163, causing flexible body portion502 to bend. As pilot needles 154, 156 are further advanced, barb 506 isturned in direction 180 degrees by deflector 163. It will be appreciatedthat the barb 506 may either be positioned in front of pilot needle 154by an amount sufficient to redirect barb 506 into the opposite directionor pilot needle 154 may advance into the corresponding aperture 152 to adepth at which the redirection of barb 506 upon the entry to aperture152 will be sufficient to redirect barb 506 into the opposite direction.Once redirected and positioned in line with the second skive, barb 506is advanced in the opposite direction by pilot needle 156 and throughthe skin tissue on the opposite side of the vertical interface 51 aspilot needle 156 is withdrawn. Once barb 506 emerges from the dermaltissue, attachment flap 504 may be bent so that barb 506 may be pushedthrough slot 508, thus securing fastener 500 in a loop and bilaterallycapturing both sides of the skin opening 50. It will also be appreciatedthat attachment flap 504 may be replaced by suitable structure onflexible body 502 for engaging a suture. The suture lock of co-pendingapplication entitled “Suture Lock Having Non-Through Bore Capture Zone,”U.S. patent application Ser. No. 10/166,161, filed Jun. 10, 2002, whichis commonly owned by the assignee of the present invention and thedisclosure of which is hereby incorporated by reference, may then beused to secure the suture to barb 506, completing the bilateral capture.In this embodiment described herein, the skives are createdsimultaneously and the fastener 400 is inserted sequentially into eachcorresponding skive from an opposite direction. Alternatively, a singleU-shaped needle could be utilized in place of pilot needles 154, 156 andboth the skives and fastener could be created and inserted sequentially.Numerous other combinations of bilateral creation of skives andinsertion of fasteners are contemplated by scope of the presentinvention.

As described herein, the fastener is oriented so that a working planedefined by the flexible body 502 of fastener 500 is substantiallyparallel to a plane generally defined by exterior surface 55 ofepidermal layer 54, and transverse to vertical interface 51. Those ofskill in the art will appreciate, however, that the working plane offastener 500 could also be oriented substantially orthogonal, oroblique, with the plane generally defined by exterior surface 55 whileremaining in a transverse orientation with respect to vertical interface51. Those of skill in the art will also appreciate that other bilateralcapture mechanical fastening systems wherein the target tissue zones arepenetrated by a fastener in sequential fashion are possible within thescope of the present invention. For instance, a semi-circular, oval, orspiral fastener may be advanced sequentially through target tissue zones70 on each side of vertical interface 51 using a mechanism that impartsa rotational motion to the fastener, but without causing interdigitationor overlapping of skin across vertical interface 51. The mechanism mayhave means for creating a semi-circular, oval or spiral skive throughwhich the fastener may be advanced, or the fastener itself may be formedfrom sufficiently rigid material and have a sharpened point so as to becapable of creating a skive as it passes through the skin. In anotheralternative embodiment providing a sequential bilateral capture motion,a fastener is provided having a cross-member connecting two legs whereinthe legs are staggered so that when the fastener is advanced into theskin in a linear fashion, one of the legs precedes the other. In stillanother embodiment, two straight fasteners comprising a shaft portionwith skin-engaging barbs are provided. These fasteners are oriented inopposite directions on either side of the vertical interface 51, and aresequentially advanced through respective skives by an applicatorassembly allowing a reversible motion.

In one embodiment, as shown in FIG. 34, a tab or other similar guidingstructure 167 projects from an exposed portion of anvil portion 140 toserve as a reference guide to locating the external surface of the skinagainst such guiding structures. Most preferably, this guiding structure167 is adapted to mate with a corresponding pair of surface guidingfeatures 169 on the internal surface of arms 302, 304 of the tissuemanipulator assembly 300 so as to provide both a tactile and visualindication of the appropriate positioning of the applicator 100 andtissue manipulator 300 relative to the vertical interface 51 of thetissue opening 50. Preferably, the guiding structure 167 and guidingfeatures 169 combine to force the applicator 100 to stay laterallycentered about the vertical interface 51 and to stay properly positionedboth horizontally and vertically. Alternatively, visual indicatorsand/or an exterior platform-like structure around the exterior ofdriving head 140 may be provided to assist the user in properpositioning of the applicator assembly 100 and the tissue manipulatorassembly 300.

FIGS. 35 and 36 show an alternate embodiment of applicator assembly 100and tissue manipulator assembly 300 in which both manipulator surfaces318 and concave areas 150 are semi-spherically shaped to provide guidingstructure in both horizontal and vertical orientations as the tissue iscompressed by the tissue manipulator 300 into the applicator 100. Inthis embodiment, there are no inward projections 320 shown for capturingthe tissue as the application of pressure to the ball-like tips 318provides both the capture and compression forces imparted to the tissue.Areas 150 on the applicator 100 are semi-spherical in shape to mate inmore than one orientation with the ball tips 318, rather than beingmerely concave to align the tissue in a single orientation.

FIG. 37 shows another alternate embodiment of applicator assembly 100 inwhich the fasteners 400 are inserted obliquely into the tissue along thevertical interface 51. In this embodiment, the penetrating needles 152,154 are oriented obliquely downward relative to the horizontal and thedistance dl on the driving head 140 is reduced. An upper projection 167extends on top of the vertical interface 51 of the opening 50 to serveas a guide and the aperture 141 between upper projection 167 and thedriving head 140 is positioned to require less rotational movement ofthe applicator assembly 100 in the plane of the vertical interface 51when the tissue is being positioned in the driving head 140 or theapplicator assembly 100 is being positioned for insertion of asubsequent fastener 400. One advantage of the oblique orientation of thefasteners 400 along the vertical interface 51 of opening 50 is that theeffective spacing between backing members 408 of adjacent fasteners 400is reduced, thereby affording the opportunity to increase the resultingholding pressure that can be applied across the vertical interface 51 toresist tearing by being able to insert more fasteners per longitudinaldistance of the opening 50.

FIG. 38 shows another embodiment of the present invention in which thetissue manipulator 300 and the applicator assembly 100 are integratedtogether into a single handheld surgical instrument 600. In thisembodiment, a manual trigger 200 is used to activate first the lateralcompression operation of the arms 302, 304 of the tissue manipulatorassembly 300 and then is further depressed to engage the deliverymechanism 128. A force translation mechanism 602 inside the handle 110in the form of a cam, wedge or similar arrangement is first engaged bythe depression of the trigger 200. Further depression of trigger 200then causes delivery mechanism 128 to be actuated. It will beappreciated that a single handheld surgical instrument 600 integratingthe structures of both the applicator assembly 100 and the tissuemanipulator assembly 300 could be arranged and operated in a number ofways. For example, two trigger actuators could be used instead of onetwo-stage actuator. Instead of arranging the tissue manipulator assembly300 and the applicator assembly 100 inline in the same orientation, thetwo assemblies 300 and 100 could be arranged to face each other in thelongitudinal orientation.

An alternative embodiment of a hand-held surgical instrument 700 using atop-down approach, as opposed to previously disclosed bottom-upembodiments, is depicted in FIGS. 40, 41, 42, 43, and 44. Hand-heldsurgical instrument 700 comprises a handle assembly 702, a tissuemanipulator assembly 704 and an applicator assembly 706. Handle assembly702 has a proximal end 708 and a distal end 710. Handle assembly 702further comprises a gripping portion 712 and a mounting portion 714.Handle assembly 702 preferably is constructed using a first handle body716 and a second handle body 718. First handle body 716 includes a pairof hollow projections 720 a, 720 b. Second handle body 718 includes apair of through bores 722 a, 722 b positioned to align with hollowprojection 720 a, 720 b. In addition, first handle body 716 includes abore 724 that aligns with a throughbore 725 located on second handlebody 718. First handle body 716 also includes another bore 726 alignedwith a throughbore 727 on second handle body 718. First handle body 716and second handle body 718 are assembled into handle assembly 702 usingfastening means 721, most typically screws. Fastening means 727 are usedto engage first handle body 716 and second handle body 718 at hollowprojection 720 a and throughbore 722 a, hollow projection 720 b andthroughbore 722 b and at bore 726 and throughbore 727. Both first handlebody 716 and second handle body 718 include a mounting bore 728presented within a mounting recess 730. Mounting bore 728 and mountingrecess 730 accommodate a spring assembly 731. Located at proximal end708 of both first handle body 716 and second handle body 718 is a pairof projections 732 a, 732 b. Projections 732 a and 732 b includeprojection bores 734 a and 734 b. Both first handle body 716 and secondhandle body 718 include an external mounting surface 740 including amounting bore 742 and a mounting pin 743.

Tissue manipulator assembly 704 in this embodiment preferably comprisesa trigger 750 having a biasing end 752 and a mounting end 754. Mountingend 754 includes an attachment block 756. Attachment block 756 includesan attachment surface 758 having a cylindrical groove 760. Attachmentblock 756 further comprises an attachment recess 762. A notch 763 isalso present within attachment block 756. A pair of opposed attachmentwalls 764 a, 764 b define attachment recess 762 along with attachmentsurface 758. A pair of opposed posts 766 a, 766 b are mounted onattachment walls 764 a, 764 b. Also present on the exterior ofattachment walls 764 a, 764 b are a pair of bores 768 a and 768 b.

Tissue manipulator assembly 704 further includes a pair of opposedtissue forms 770 a and 770 b. Tissue form 770 b is further depicted inFIGS. 45 and 46, though it is to be understood that tissue form 770 aincludes the same features as tissue form 770 b but in a mirror-imagearrangement. Tissue forms 770 b includes an attachment end 772 and agripping end 774. Attachment end 772 includes an opening 776 having apair of opposed and aligned attachment bores 778, 778 b. Tissue form 770b further includes a mounting bore 780, a post bore 782, and a limitbore 784. Limit screw 786 rotatably inserts into limit bore 784. On theexterior of tissue forms 770 a, 770 b is located a guide projection 788.Grasping end 774 is defined by an interior surface 790 and an exteriorsurface 792. Interior surface 790 is further defined by a proximal jaw794, a distal jaw 796, an arcuate recess 798, and a bottom lip 800.

Applicator assembly 706 preferably includes an applicator trigger 802.Applicator trigger 802 includes a biasing end 804, a driving end 806,and a rotational through bore 808. A fulcrum member 810, depicted as ascrew, slidingly inserts through throughbore 725, throughbore 808 andinto bore 724. Fulcrum member 810 allows for rotational travel ofapplicator trigger 802 as well as providing additional fasteningstrength between first handle body 716 and second handle body 718.Driving end 806 includes a tip 812. Applicator assembly 706 furtherincludes an insertion block 814 more clearly depicted in FIGS. 47, 48and 49. Insertion block 814 includes an attachment end 816 and aninsertion end 818. On the top of insertion block 814 is a hollow channel820. A pair of attachment bores 822 a, 822 b on one side of hollowchannel 820 are in alignment with a pair of attachment bores 824 a, 824b present on the other side of hollow channel 820. Insertion block 814also includes a pair of alignment bores 823 a, 823 b. Finally, insertionblock 814 includes another pair of post bores 825 a, 825 b toaccommodate a rotation post 827. Insertion end 818 is defined by aninsertion head 826. Present on either side of insertion head 826 is anarcuate capture zone 828 a, 828 b. Within both capture zones 828 a, 828b is an alignment indicator 830. The alignment indicator could include abore or horizontal ledge. An insertion cavity 831 and a delivery cavity832 define a continual opening extending from attachment end 816 toinsertion end 818. An attachment slide 833 is dimensioned to fit withininsertion cavity 831 and delivery cavity 832. Attachment slide 833includes an attachment cavity 834 defined by a pair of cavity walls 836a, 836 b. An insertion slide 838 is also dimensioned to fit withininsertion cavity 831 and delivery cavity 832. Insertion slide 838comprises a pair of piercing members 840 a, 840 b. Piercing members 840a, 840 b each include an internal arcuate section 842. Piercing members840 a, 840 b are connected via a backspan 844.

Surgical instrument 700, as described is a single shot design in which asingle bioabsorbable fastener 1010, as depicted in FIGS. 50 and 51, andas further described in concurrently filed U.S. Patent Applicationentitled, “Dynamic Bioabsorbable Fastener For Use In Wound Closure,”filed Jun. 25, 2003, which is commonly assigned to the assignee of thepresent application and is hereby incorporated by reference in itsentirety. Fastener 1010, as shown in FIG. 50, comprises a backspan 1012operably connecting a pair of arms 1014 a, 1014 b. AS depicted, fastener1010 has a diameter 1013 that is consistent throughout backspan 1012 andarms 1014 a, 1014 b. Arms 1014 a, 1014 b each preferably include arounded tip 1016 a, 1016 b connected to an internally projecting cleat1018 a, 1018 b. Fastener 1010 includes an exterior surface 1020 and aninterior surface 1022. Interior surface 1022 as defined by backspan1012, arms 1014 a, 1014 b and cleats 1018 a, 1018 b defines an internaltissue capture zone 1024. Each cleat 1018 a, 1018 b includes aninsertion face 1026, a cleat tip 1028 and a rear surface 1030. Rearsurface 1030 intersects arms 1014 a, 1014 b defining a capture area 1032a, 1032 b. Each arm 1014 a, 1014 b of fastener 1010 has an insertionwidth 1034 which is defined across the widest width across arm 1014 aand cleat 1018 a or arms 1014 b and cleat 1018 b. Generally, fastener1010 is dimensioned to fit between piercing member 840 a, 840 b andbackspan 844. Fastener 1010 is positioned such that the arms 1014 a,1014 b reside within the internal arcuate sections 842 as depicted inFIG. 52. In an alternative embodiment of fastener 1010 depicted in FIG.51, the diameter 1013 can be proportioned throughout the backspan 1012and arms 1014 a, 1014 b to provide desired strength levels withoutaffecting the interaction of fastener 1010 and piercing members 840 a,840 b.

Preferably, surgical instrument 700 is used in a through-and-throughbilateral tissue fastening technique 860 for bilateral fastening ofdermal tissue. The through-and-through bilateral fastening technique 860is depicted in FIGS. 57, 58, 59, 60, 61, 62 and 63. While thethrough-and-through procedure is described with reference to closure ofa skin wound, one of skill in the art will recognize that thethrough-and-through procedure can be effectively applied in otherapplications involving closure of tissue openings such as fascia,internal organs, vessels and vasculature, or with tissue attachmentsincluding skin grafting, bladder and other anatomic tissues.

Generally, a first step of the through-and-through bilateral fasteningtechnique 860 is to load fastener 1010 between piercing member 840 a,840 b and backspan 844. As depicted in FIG. 53, fastener 1010 residessnugly within internal arcuate sections 842. As shown in FIG. 54,piercing member 840 a, and corresponding piercing member 840 b, have apiercing cross-section 862. Similarly, cleat 1018 a, and correspondingcleat 1018 b, have a cleat cross-section 864 as shown in FIG. 55.Fastener 1010 is specifically designed such that the insertion width1034 exceeds the piercing cross-section 862. As such, cleats 1018 a,1018 b will protrude inwardly from piercing members 840 a, 840 b, asillustrated in FIG. 53.

Once surgical instrument 700 has been loaded with fastener 1010,insertion head 826 is inserted into and positioned within a tissue wound862 having a pair of opposed sides 864 a, 864 b. Surgical instrument 700should be in an open disposition 866, as shown in FIG. 56, in which thetissue forms 770 a, 770 b are substantially spaced apart from insertionhead 826. Using a grasping device 867, most typically being a standardsurgical forceps, as depicted in FIG. 57, a medical professional graspsthe opposed sides 864 a, 864 b, and places the opposed side 864 a, 864 bin proximity to insertion head 826 in an everted disposition 869, asshown in FIG. 58. At this point, opposed side 864 a is positioned withincapture zone 828 a while opposed side 864 b is positioned within capturezone 828 b. Using alignment indicator 830, a medical professional canproperly position opposed sides 864 a, 864 b with respect to thevertical height of capture zones 828 a, 828 b as shown in FIG. 59. Whenproperly positioned, the dermal layer 56 of opposed sides 864 a, 864 bis in contact with the surface of capture zones 828 a, 828 b.

After opposed sides 864 a, 864 b are properly positioned within capturezones 828 a, 828 b, the medical professional biases trigger 750 in anupward direction causing tissue forms 770 a, 770 b to simultaneouslyclose upon opposing sides 864 a, 864 b within tissue zones 828 a, 828 b,as shown in FIG. 60. Surgical instrument 700 is referred to being in a871 capture disposition 866. Capture disposition 871 is accomplished bydirecting trigger 750 in an upward direction causing trigger 750 torotate about rotation post 827. Rotation post 827 operably joins trigger750 and insertion head 814 in conjunction with post bores 825 a, 825 b,cylindrical groove 760 and bores 768 a, 768 b. As trigger 750 is biasedupward, mounting end 754 travels in a downward arc causing opposed posts766 a, 766 b to move downward and contact guide projection 788 on tissueforms 770 a, 770 b. This causes tissue forms 770 a, 770 b to rotate in adownward direction around mounting pin 743 such that the interiorsurface 790 of tissue forms 770 a, 770 b is in close proximity tocapture zones 828 a, 828 b. As tissue forms 770 a, 770 b rotatedownwardly, the bottom lip 800 on interior surface 790 prevents tissue,especially the elastic dermal layer 56, from escaping out the bottom ofcapture zones 828 a, 828 b. Due to precise dimensioning of insertionhead 826 and tissue forms 770 a, 770 b, the target tissue zone 70 aspreviously described, is presented within both opposing sides 864 a, 864b. In addition, the combination of proximal jaw 794 and distal jaw 796on tissue forms 770 a, 770 b, grasp and stretch opposed sides 864 a, 864b causing opposed sides 864 a, 864 b to be held tightly betweeninsertion head 826 and tissue forms 770 a, 770 b to further reduce thepotential for perforating the epidermal layer 54 of opposed sides 864 a,864 b, as depicted in FIG. 61.

Once the opposed sides 864 a, 864 b are captured within insertion head826 and tissue forms 770 a, 770 b, the medical professional directsbiasing end 804 of applicator trigger 802 in a distal direction as shownin FIG. 62. As biasing end 804 travels rearward, trigger 802 rotatesabout fulcrum member 810 causing tip 812 on driving end 806 to travel ina proximal direction. Tip 812, positioned within attachment cavity 834,contacts cavity wall 836 a causing attachment slide 833 to move in aproximal direction through delivery cavity 832. Attachment slide 833abuts insertion slide 838 causing insertion slide 838 to also move in aproximal direction through delivery cavity 832. As insertion slide 838moves in a proximal direction, piercing members 840 a, 840 b areadvanced sequentially out of delivery cavity 832, into capture zones 828a, 828 b, into target tissue zones 70 of opposed sides 864 a, 864 b andinto insertion cavity 831. As piercing members 840 a, 840 b are advancedproximally, fastener 1010 is simultaneously advanced out of deliverycavity 832, into capture zones 828 a, 828 b, into target tissue zones 70of opposed sides 864 a, 864 b and into insertion cavity 831 as shown inFIG. 52. As previously described, insertion width 1034 exceeds thepiercing cross-section 862. Consequently, the holes cut in the targettissue zone 70 by piercing members 840 a, 840 b must stretch toaccommodate insertion width 1034. As cleats 1018 a, 1018 b are advancedinto the holes cut in target tissue zone 70, the holes pierced bypiercing member 840 a, 840 b in dermal layer 56 are forced toelastically stretch past the cleat tips 1028. The dermal layer 56 thenrebounds and elastically snaps into capture areas 1032 a, 1032 b.

Using application assembly 706, the medical professional directs biasingend 804 of applicator trigger 802 in a proximal direction causingtrigger 802 to rotate about fulcrum member 810 causing tip 812 ondriving end 806 to travel in a distal direction. Tip 812, positionedwithin attachment cavity 834, contacts cavity wall 836 b causingattachment slide 833 to move in a distal direction through deliverycavity 832. Attachment slide 833 causes insertion slide 838 to also movein a proximal direction such that piercing members 840 a, 840 b aresequentially withdrawn from insertion cavity 831, target tissue zones70, capture zones 828 a, 828 b and into delivery cavity 832. However,fastener 1010 remains within target tissue zones 70 as cleats 1018 a,1018 b, prevent fastener 1010 from being withdrawn due to captureddermal layer elastically retained within capture areas 1032 a, 1032 b.Fastener 1010 remains within tissue wound 862 such that backspan 1012traverses the gap between opposed sides 864 a, 864 b with the dermallayers 56 forcibly approximated to promote the biological healingprocess. Once fastener 1010 has been placed, the medical professionaldirects trigger 750 in a downward direction causing tissue forms 770 a,770 b to rotate upwardly and release opposed sides 864 a, 864 b suchthat surgical instrument 700 is back in open disposition 866. Thethrough-and-through bilateral fastening technique 860 is typicallyrepeated along the length of tissue wound 862 resulting in the closureof wound 862, as depicted in FIG. 63.

Another alternative embodiment of a handheld surgical instrument 900 isdepicted in FIGS. 64-68. Handheld surgical instrument 900 comprises abody assembly 902, a trigger assembly 904, a tissue manipulationassembly 906, an applicator assembly 908, and a fastener assembly 909.Body assembly 902 comprises a molded housing 910 connected via aplurality of fastening members 912. Molded housing 910 includes aproximal end 914 and a distal end 916. Molded housing 910 furtherincludes a bottom opening 918.

Trigger assembly 904 comprises a trigger 920, a manipulation bore 924, aratchet member 925, an interface channel 926 and a top surface 928. Topsurface 928 includes an upper engagement portion 930. Upper engagementportion 930 interfaces with a spring assembly 932.

Tissue manipulation assembly 906 comprises a pair of connecting arms 934a, 934 b and a pair of tissue forms 936 a, 936 b. Tissue forms 936 a,936 b include a grasping portion 937 substantially similar to tissueforms 770 a, 770 b, which have been previously described. On an exteriorsurface of tissue forms 936 a, 936 b is a molded guide ramp 938performing the same function as guide projection 788, as previouslydescribed. Each tissue form 936 a, 936 b includes a pair of mountingbores 940 a, 940 b.

Applicator assembly 908 includes an advancing assembly 942 comprised ofa rotation member 944 and a lever member 946. Rotation member 944 iscomprised of a pair of opposed rotation elements 948 a, 948 b. Eachrotation element 948 a, 948 b includes a distal bore 950, a fulcrum bore952, and a proximal bore 954. Rotation elements 948 a, 948 b are theninterconnected with a distal connector 956 through distal bores 950, afulcrum connector 958 through fulcrum bores 952, and a proximalconnector 960 mounted through proximal bores 954. Lever member 946includes distal end 962 and a proximal end 964. A spring assembly 959 ismounted on fulcrum connector 958. Distal end 962 has a channel 966.Lever member 946 includes a fulcrum bore 968 having a fulcrum connector969. Located at proximal end 964 is a connecting tip 970. Applicatorassembly 908 further includes insertion slide 972. Insertion slide 972comprises a distal end 974 and a proximal end 976. Located at the distalend 974 of insertion slide 972 is an attachment cavity 978 defined by apair of attachment walls 980 a, 980 b. At the proximal end 976 ofinsertion slide 972 is a pair of opposed piercing members 982 a, 982 b.Piercing members 982 a, 982 b each include an internal arcuate section984 a, 984 b. Piercing members 982 a, 982 b are operably joined atbackspan member 986. Applicator assembly 908 further includes aninsertion head 988. Insertion head 988 includes an arcuate capture zone990. Throughout the length of insertion head 988 is an insertion cavity992 dimensioned to accommodate the insertion slide 972.

Fastener assembly 909 in this embodiment comprises a fastener stack 994,consisting of a plurality of bioabsorbable fasteners 1010 previouslydepicted in FIGS. 50 and 51, a fastener housing 996, and a spring feedassembly 998. Fastener assembly 909 can further include a removablelocking member 1000. Removable locking pin 1000 allows a surgicalinstrument 900 to be shipped fully assembled to facilitate ease of useby a physician. Preferably., removable locking pin 1000 prevents springfeed assembly 998 from applying force directly to fastener stack 994during shipment or storage so that the bioabsorbable fasteners 1010 donot deform after prolonged exposure to the spring force.

Preferably, surgical instrument 900 is used with a through-and-throughbilateral tissue fastening technique similar to that of surgicalinstrument 700 as previously described. One procedural difference beingthat surgical instrument 900 is a multi-shot design in which a pluralityof fasteners 1010 come preloaded, thus eliminating any handloading ofindividual fasteners 1010. Another procedural difference being thatsurgical instrument 900 includes trigger assembly 904 which incorporatesa two-stage mechanism sequentially operating both the tissuemanipulation assembly 906 and applicator assembly 908.

With respect to grasping tissue with tissue manipulation assembly 906,the medical profession squeezes body assembly 902 and trigger assembly904 causing trigger 920 rotate about ratchet member 925. As trigger 920enters bottom opening 918, connecting arms 934 a, 934 b rotate in anopposed direction and contact the molded guide ramp 938 on tissue forms936 a, 936 b causing to tissue forms 936 a, 936 b to rotate about arotation member coupling mounting bores 940 a, 940 b with body assembly902. Eventually, tissue forms 936 a, 936 b rotate to a grasping positionon either side of insertion head 988. Following manipulation of tissueforms 936 a, 936 b to a grasping position, continual squeezing of bodyassembly 902 and trigger assembly 904 causes trigger 920 to insertfurther into bottom opening 918 such that interface channel 926 slidesaround distal connector 956. As trigger 920 inserts further into bottomopening 918, distal connector 956 reaches and end of interface channel926 causing rotation member 944 to rotate about fulcrum connector 958such that proximal connector 960 moves in a downward direction. Downwardmovement of proximal connector 960 causes channel 966 to move in adownward direction resulting in lever member 946 rotating about fulcrumconnector 969. As channel 966 moves downward, proximal end 964 moves ina forward direction causing connecting tip 970 to direct insertion slide972 to advance toward insertion head 988. As insertion head 988advances, piercing members 982 a, 982 b and backspan member 986cooperatively capture a bottom most fastener 1010 from fastener stack994. Fastener 1010 is advanced through the capture zone 990 and into thetarget tissue zones 70 as previously described with respect to surgicalinstrument 700.

As trigger 920 is further squeezed and inserted into opening 918,ratchet member 925 releases. As piercing members 982 a, 982 b retractpast fastener stack 994, spring feed assembly 998 advances the bottommost fastener 1010 into position for a future capture by piercingmembers 982 a, 982 b. As ratchet member 925 releases, spring assembly932 interacts with upper engagement portion 930 allowing trigger 920 toreturn to its original position which in turn caused tissue forms 936 a,936 b to release the grasped tissue. In addition, spring assembly 959causes rotation member 944 to return to its original orientation suchthat piercing members 982 a, 982 b are retracted.

In another representative embodiment of the invention as shown in FIG.69, a subcuticular stapler 1100 can comprise a body assembly 1102defining a head portion 1104. The head portion 1104 generally includes aproximal wall 1106 from which a bioabsorbable fastener or staple, forexample, fastener 400 is introduced into skin tissue. The proximal wall1106 generally defines a wall width 1108. The head portion 1104 furthercomprises an upper projecting member 1110 that terminates at a distalupper end 1112. The upper projecting member 1110 can have an uppermember width 1114. The head portion 1104 can further comprise a lowerdeflector shelf 1116 having a lower shelf width 1118. As shown in FIG.69, the wall width 1108 and lower shelf width 1118 can be essentiallyequal while the upper member width 1114 is greater than that wall width1108 so as to define an upper guide member 1120. Upper guide member 1120serves to guide skin tissue past a proximal wall corner 1122 and into acapture area 1124. In variations to subcuticular skin stapler 1100, thelower shelf width 1118 can be greater than the wall width 1108 so as todefine a lower guide member 1126 as shown in FIG. 70. In anothervariation illustrated in FIG. 71, the lower deflector shelf 1116 canextend past the capture area 1124 and include a distal lower end 1128.The distal lower end 1128 can define a distal lower width 1130 that isessentially equal to upper member width 1114 and which can be greaterthan or equal to the lower shelf width 1118.

Although the present invention has been described with respect to thevarious embodiments, it will be understood that numerous insubstantialchanges in configuration, arrangement or appearance of the elements ofthe present invention can be made without departing from the intendedscope of the present invention. Accordingly, it is intended that thescope of the present invention be determined by the claims as set forth.

1. A method of deploying a bioabsorbable fastener into two sides of anincision or wound in skin tissue, comprising: everting each of the twosides of the incision or wound to present an inner surface of each ofthe two sides; inserting a bioabsorbable fastener into the exposed innersurfaces by simultaneously inserting each of a pair of legs of thefastener into one of the two exposed inner surfaces from above andgenerally vertical relative to the external surface of the skin tissue;and releasing the two sides of the incision or wound to leave thebioabsorbable fastener below the external surface of the skin tissue,whereby the two sides of the incision or wound are maintained inapproximation by the bioabsorbable fastener as the bioabsorbablefastener transitions in response to wound stress from an insertiondisposition in which the pair of legs reside in parallel relation toeach other and in a substantially perpendicular orientation relative tothe external surface of the skin tissue to a subsequent disposition inwhich the pair of legs reside in non-parallel relation to each other. 2.A mechanism for deploying a bioabsorbable fastener into skin tissuehaving an incision or wound, comprising: a tissue manipulation assemblyhaving: a first tissue form configured to contact an external surface ofthe skin tissue on a first side of the incision or wound; and a secondtissue form configured to contact the external surface of the skintissue on a second side of the incision or wound, the tissuemanipulation assembly configured to evert the skin tissue on the firstside and the second side relative to the external surface of the skintissue to expose a dermal layer of each of the first side and the secondside of the incision or wound; a generally U-shaped bioabsorbablefastener having a first leg connected to a second leg by a cross member;and an applicator assembly configured to deploy the bioabsorbablefastener into the incision or wound, the applicator assembly having: afirst piercing member adapted to releasably hold the first leg; and asecond piercing member adapted to releasably hold the second leg, theapplicator assembly configured to simultaneously deploy the first leginto the dermal layer of the first side of the incision or wound and thesecond leg into the dermal layer of the second side of the incision orwound, the bioabsorbable fastener being deployed from above andgenerally obliquely downward relative to the external surface of theskin tissue, whereby the sides of the incision or wound are maintainedin approximation by the bioabsorbable fastener for a period of timeafter the bioabsorbable fastener is deployed.
 3. A subcuticular skinstapler, comprising: a body assembly including one or more biocompatiblestaples, the body assembly defining a head portion configured forengaging a skin wound, the head portion including a proximal wallwherein lower deflector shelf and an upper projecting member extenddistally from the proximal wall, the lower deflector shelf, upperprojecting member and proximal wall defining a capture areatherebetween, said capture area configured to receive skin tissue, theupper projecting member having an upper member width exceeding a wallwidth of the proximal wall such that an upper guide member is defined bythe upper projecting member, said upper guide member guiding the skintissue past a lower wall corner of the proximal wall and into thecapture area.
 4. The subcuticular skin stapler of claim 3, wherein thelower deflector shelf has a shelf width, said shelf width being greaterthan the wall width so as to define a lower guide member.
 5. Thesubcuticular skin stapler of claim 4, wherein the lower deflector shelffurther includes a distal lower end having a distal lower end width,wherein said distal lower end width is equal to the upper member width.6. The subcuticular skin stapler of claim 5, wherein the distal endwidth is equal to the shelf width.